An adaptive randomized trial of dialectical behavior therapy and cognitive behavior therapy for binge-eating

Abstract

Background: Early weak treatment response is one of the few trans-diagnostic, treatment-agnostic predictors of poor outcome following a full treatment course. We sought to improve the outcome of clients with weak initial response to guided self-help cognitive behavior therapy (GSH).

Method: One hundred and nine women with binge-eating disorder (BED) or bulimia nervosa (BN) (DSM-IV-TR) received 4 weeks of GSH. Based on their response, they were grouped into: (1) early strong responders who continued GSH (cGSH), and early weak responders randomized to (2) dialectical behavior therapy (DBT), or (3) individual and additional group cognitive behavior therapy (CBT+).

Results: Baseline objective binge-eating-day (OBD) frequency was similar between DBT, CBT+ and cGSH. During treatment, OBD frequency reduction was significantly slower in DBT and CBT+ relative to cGSH. Relative to cGSH, OBD frequency was significantly greater at the end of DBT (d = 0.27) and CBT+ (d = 0.31) although these effects were small and within-treatment effects from baseline were large (d = 1.41, 0.95, 1.11, respectively). OBD improvements significantly diminished in all groups during 12 months follow-up but were significantly better sustained in DBT relative to cGSH (d = -0.43). At 6- and 12-month follow-up assessments, DBT, CBT and cGSH did not differ in OBD.

Conclusions: Early weak response to GSH may be overcome by additional intensive treatment. Evidence was insufficient to support superiority of either DBT or CBT+ for early weak responders relative to early strong responders in cGSH; both were helpful. Future studies using adaptive designs are needed to assess the use of early response to efficiently deliver care to large heterogeneous client groups.

Keywords: Bulimia; binge-eating disorder; cognitive behavior therapy; dialectical behavior therapy; guided self-help; stepped care.

Conflict of interest statement

Declaration of Interest

With regards to disclosure of financial relationships, the first author discloses annual royalties from Guilford Press and has consulted for Shire Pharmaceuticals. The second author discloses royalties from Norton Books and Cengage Publishing for academic books and chapters.

Figures

Fig. 1.

Consort flow diagram of Stage 1 (GSH) and Stage 2 (cGSH, DBT, and CBT+).

Fig. 2.

Objective binge-day frequency changes in DBT and CBT+ groups relative to early strong responders in cGSH at the end of treatment and at follow-up.